3,951 research outputs found

    Ein Ur III-Text aus Münsteraner Privatbesitz

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    Uppsatsen behandlar hur USA: s president George W Bush använder civilreligiösa inslag i sin retorik under sitt första år som president. Han startade ämbetsperioden med att använda religiösa anspelningar i sitt installationstal., för att sedan fortsätta i samma anda hela året. Bush är inte den första presidenten att använda sådana retoriska knep. Ända sedan USA: s grundande har presidenterna förstärkt sin talarkonst genom att hänvisa till Gud och att landet är utvalt av Gud - ett nytt Israel. Landets presidenter har alltid varit mer eller mindre övertygade om att Gud står på USA: s sida. Detta trots att det första tillägget i USA: s konstitution föreskriver en separation mellan religion ochstat. Uppsatsen analyseras utifrån en innehållsanalys, som är en vanlig metod för att analysera politiska tal. Vår innehållsanalys består av åtta olika kategorier som speglar Bushs civilreligiösa retorik väl. Resultatet visar att Bush som president anser att det är självklart att en amerikansk president har en gudstro. Han använder ett religiöst språkbruk genom att citera ur Bibeln och Koranen i sina offentliga framträdanden. Han säger sig vara övertygad om att USA är utvalt av Gud att styra över världen. En stor del av Bushs civilreligiösa retorik går att hitta i att han försöker ena nationen genom att hänvisa till landets historia. Han visar ofta hur krigshjältar och presidenter har offrat sina liv för USA. Vi anser att Bush använder civilreligiös retorik för att ena nationen vid svåra tillfällen. Efter terrorattacken den 11: e september 2001 ökar frekvensen av civilreligion hos Bush. Det är tydligt att den amerikanske presidenten vill ena en nation i chock. Vi menar också att det av tradition förväntas att USA:s president har ett civilreligiöst språkbruk. Vi menar att Bush använder civilreligionen som en ursäkt för att inte genomföra reella politiska förändringar i samhället

    Automatic grid refinement criterion for lattice Boltzmann method

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    In all kinds of engineering problems, and in particular in methods for computational fluid dynamics based on regular grids, local grid refinement is of crucial importance. To save on computational expense, many applications require to resolve a wide range of scales present in a numerical simulation by locally adding more mesh points. In general, the need for a higher (or a lower) resolution is not known a priori, and it is therefore difficult to locate areas for which local grid refinement is required. In this paper, we propose a novel algorithm for the lattice Boltzmann method, based on physical concepts, to automatically construct a pattern of local refinement. We apply the idea to the two-dimensional lid-driven cavity and show that the automatically refined grid can lead to results of equal quality with less grid points, thus sparing computational resources and time. The proposed automatic grid refinement strategy has been implemented in the parallel open-source library Palabos

    Magnetic inversion symmetry breaking and ferroelectricity in TbMnO3

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    TbMnO3 is an orthorhombic insulator where incommensurate spin order for temperature T_N < 41K is accompanied by ferroelectric order for T < 28K. To understand this, we establish the magnetic structure above and below the ferroelectric transition using neutron diffraction. In the paraelectric phase, the spin structure is incommensurate and longitudinally-modulated. In the ferroelectric phase, however, there is a transverse incommensurate spiral. We show that the spiral breaks spatial inversion symmetry and can account for magnetoelectricity in TbMnO3.Comment: 4 pages revtex, accepted by Phys. Rev. Lett. on June 21, 200

    Characterization and benchmarking of a phase-sensitive two-qubit gate using direct digital synthesis

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    We implement an iSWAP gate with two transmon qubits using a flux-tunable coupler. Precise control of the relative phase of the qubit-control pulses and the parametric-coupler drive is achieved with a multi-channel instrument called Presto using direct digital synthesis (DDS), a promising technique for scaling up quantum systems. We describe the process of tuning and benchmarking the iSWAP gate, where the relative phase of the pulses is controlled via software. We perform the iSWAP gate in 290 ns, validate it with quantum-state tomography, and measure 2\% error with interleaved randomized benchmarking

    On the rotating wave approximation in the adiabatic limit

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    I revisit a longstanding question in quantum optics; When is the rotating wave approximation justified? In terms of the Jaynes-Cummings and Rabi models I demonstrate that the approximation in general breaks down in the adiabatic limit regardless of system parameters. This is explicitly shown by comparing Berry phases of the two models, where it is found that this geometrical phase is strictly zero in the Rabi model contrary to the non-trivial Berry phase of the Jaynes-Cummings model. The source of this surprising result is traced back to different topologies in the two models.Comment: 8 pages, 3 figure

    Primary beam effects of radio astronomy antennas -- II. Modelling the MeerKAT L-band beam

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    After a decade of design and construction, South Africa's SKA-MID precursor MeerKAT has begun its science operations. To make full use of the widefield capability of the array, it is imperative that we have an accurate model of the primary beam of its antennas. We have taken available L-band full-polarization 'astro-holographic' observations of three antennas and a generic electromagnetic simulation and created sparse representations of the beams using principal components and Zernike polynomials. The spectral behaviour of the spatial coefficients has been modelled using discrete cosine transform. We have provided the Zernike-based model over a diameter of 10 deg averaged over the beams of three antennas in an associated software tool (EIDOS) that can be useful in direction-dependent calibration and imaging. The model is more accurate for the diagonal elements of the beam Jones matrix and at lower frequencies. As we get more accurate beam measurements and simulations in the future, especially for the cross-polarization patterns, our pipeline can be used to create more accurate sparse representations of MeerKAT beams.Comment: 16 pages, 18 figures. This is a pre-copyedited, author-produced PDF of an article accepted for publication in MNRAS following peer review. The version of record [K. M. B. Asad et al., 2021] is available online at: https://doi.org/10.1093/mnras/stab10

    Bosonic String Quantization in Static Gauge

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    The bosonic string in D dimensional Minkowski space-time is quantized in static gauge. It is shown that the system can be described by D-1 massless free fields constrained on the surface L_m = 0, for m \neq 0, where L_m are the generators of conformal transformations. The free fields are quantized and the physical states are selected by the conditions L_m|phys>=0, for m>0. The Poincar\'e group generators on the physical Hilbert space are constructed and the critical dimension D=26 is recovered from the commutation relations of the boost operators. The equivalence with the covariant quantization is established. A possible generalization to the AdS string dynamics is discussed.Comment: 10 page

    School tuck shops in South Africa—an ethical appraisal

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    It can be postulated that schools have an ethical responsibility to protect children from an unhealthy food environment. Against the backdrop of stunting, overweight and micronutrient deficiencies prevalent in South African children, the aim of this scoping study is to review information available on foods sold to school children within an ethical framework. While some schools have a formal tuck shop, at other schools, food vendors sell food either on or outside the school premises. Ten studies, of which two were national, fit the selection criteria for this study. Available data show that mostly unhealthy food options are sold to South African school children; with low-nutrient energy-dense foods (e.g. chips, sweets) and sugar sweetened beverages being the most popular. The Integrated School Health Policy provide a policy framework for achieving healthy school food environments in South Africa, and several guidelines are available in South African to assist school tuck shops to sell healthier options. Children’s preference for unhealthy foods, the cost of healthier food options and a lack of proper facilities may however be barriers for implementing healthy tuck shops. An action stronger than merely providing guidelines may therefore be needed. Cognisance needs to be taken of conflicting value based arguments within ethical perspectives. Given these conflicts, the authors argue that an Ethics of Responsibility contributes to the debate of the best and supports the notion that society at large has a responsibility to protect vulnerable communities of which school children are part. Presently an ethical vacuum exists in terms of rights and responsibilities which this study hopes to address.DHE
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